1,3-dithietanes

ABSTRACT

NOVEL 2-SULFONYLIMINO-1,3-DITHIETANES AND 2-METHYLENE1,3-DIEHTIETANES ARE DESCIRBED. THESE COMPOUNDS, AND RELATED KNOWN ONES, POSSESS HERBICIDAL, MICROBIOCIDAL, MOLLUSCICIDAL AND NEMATOCIDAL PROPERTIES.

United States Patent 3,772,331 1,3-DITHIETANES Stanley A. Greenfield,Ambler, Pa., assignor to Rohm and Haas Company, Philadelphia, Pa. NoDrawing. Filed Dec. 21, 1970, Ser. No. 100,297 Int. Cl. C07d 69/00 US.Cl. 260-327 M 6 Claims ABSTRACT OF THE DISCLOSURE Novel2-sulfonylimino-l,3-dithietanes and Z-methylene- 1,3-diethietanes aredescribed. These compounds, and related known ones, possess herbicidal,.microbiocidal, molluscicidal and nematocidal properties.

This invention is concerned with biocidal compounds of the1,3-dithietane class. They may be depicted by the general formula:

wherein X is (a) An R S0 N=group wherein R is alkyl of 1 to 12 carbonatoms; benzyl optionally substituted with lower alkyl, lower alkoxy,halogen preferably chlorine, and mtro groups; phenyl and phenylsubstituted with lower a1- kyl, lower alkoxy, halogen preferablychlorine, and n tro groups; di(lower alkyl amino); l-morpholinyl;l-pipendyl and l-pyrrolidyl groups, and

(b) an R R C=group wherein R is hydrogen, bromo, chloro, cyano, an ROC(O)-group wherein R 1s a lower alkyl group,N-(3,4-dichlorophenyl)-carbamyl, N-(4-dimethylaminophenyl)-carbamyl orN-(4-mtrophenyl)carbamyl; when R is hydrogen R is cyano, mtro or an RC(O)-group wherein R is a lower alkyl or a phenyl group; where R isbromo or chloro R is nitro; when R is cyano R is cyano, an R OC(O)-groupwhere1n R 1s a lower alkyl group, an R NHC(O)-group wherein R ishydrogen or a lower alkyl group or an R 80 group wherein R is phenyl,phenyl substituted with lower alkyl, lower alkoxy, halogen preferablychloro or nitro, or a lower alkyl group; when R is an R OC(O)-group R isan R OC(O)-group wherein R is a lower alkyl group; when R isN-(3,4-dichlorophenyl)-carbamyl, N-(4-d1- methylaminophenyl)-carbamyl orN-(4-nitrophenyl)-carbamyl R3 is arenesulfonyl wherein arene 1s benzene,naphthalene or benzene substituted with lower alkyl, lower alkoxy,halogen preferably chloro, or nitro.

The novel compounds of this invention are of two main types:

( l) 2-sulfonylimino-1,3-dithietanes and (2)Z-methylene-l,3-dithietanes.

The novel 2-sulfonyl-1,3-dithietanes have the general formula:

wherein R is alkyl of 1 to 12 carbon atoms; benzyl optionallysubstituted with lower alkyl, lower alkoxy, halogen preferably chlorine,and nitro groups; phenyl substituted with lower alkyl, lower alkoxy,halogen preferably chlorine, and nitro groups; di(lower alkyl amino); 1-morpholinyl; l-piperidyl and l-pyrrolidyl groups.

3,772,331 Patented Nov. 13, 1973 (III) wherein R is hydrogen, bromo,chloro, cyano, an

R OC 0) -group wherein R is a lower alkyl group,N-(3,4-dichlorophenyl)-carbarnyl, N-(4-dimethylaminophenyl)-carbamyl orN-(4-nitrophenyl)-carbamyl; when R is hydrogen R is cyano, nitro or an RC(O)-group wherein R is a lower alkyl group or a phenyl group; when R isbromo or chloro R is nitro; when R is cyano R is an R OC(O)- wherein Ris a lower alkyl group, an R NHC(O)-group wherein R is hydrogen or alower alkyl group, or an R group wherein R is phenyl, phenyl substitutedwith lower alkyl, lower alkoxy, halogen preferably chloro or nitro, or alower alkyl group; when R is an R OC(O)- group R is an R OC(O)-group'wherein R is a lower alkyl group; when R isN-(3,4-dichlorophenyl)-carbamyl, N-(4-dimethylaminophenyl)-carbamyl orN-(4-nitrophenyl)-carbamyl R is arenesulfonyl wherein arene is benzene,naphthalene or benzene substituted with lower alkyl, lower alkoxy,halogen, preferably chloro, or nitro.

By lower alkyl, in the above group definitions, is meant an alkyl group,straight or branched chain, of 1 to 6 carbon atoms.

The 1,3-dithietanes are relatively unknown chemicals. Addor in the J. ofHeterocyclic Chemistry 1, 381-7 (1970) gives a preparation of theZ-benzenesulfonylimino derivative. In US. Pat. 3,484,455 there aredisclosed several Z-substituted imino-1,3-dithietanes wherein thesubstituents on the imino group are acyl, alkyl, aralkyl and aryl. TheRepublic of South African patent application 1064 (1968) discloses2-phosphinylimino-1,3-dithietanes. The structure of the desaurins hasbeen given a limited study. Chan et al. discusses the chemistry of the2,4-bismethylene-1,3-dithietanes in Tetrahedron 26, 1493 (1970).Canadian Pat. 850,668 describes the properties ofZ-cyanoimino-1,3-dithietane.

Exemplary compounds which fall within the defined class of2-sulfonylimino-1,3-dithietanes are:

2-methylsulphonylimino-1,3-dithietane2-isopropylsulphonylimino-1,3-dithietane2-hexylsulphonylimino-1,3-dithietane 2-.toctylsulphonylimino-1,3-dithietane 2-nonylsulphonylimino-1,3-dithietane2-dodecylsulphonylimino-l,3-dithietane2-p-methy1benzylsulphonylimino-1,3-dithietane2-0-chlorobenzylsulphonylimino-1,3-dithietane2-m-bromobenzylsulphonylimino-1,3-dithietane2p-nitrobenzylsulphonylimino-1,3-dithietane2-p-t-butylphenylsulphonylimino-1,3-dithietaneZ-p-fluorophenylsulphonylirnino-1,3-dithietane2-m-nitrophenylsulphonylimino-1,3-dithietaneZ-diethylaminosulphonylimino-1,3-dithietane2-methylethylaminosulphonyl-1,3-dithietane2-dihexylaminosulphonylimino-1,3-dithietane 2-( l-morpholinyl)sulphonylimino-1,3-dithietane Exemplary compounds which fall within thedefined class of 2-methylene-1,3-dithietanes are:

Z-acetylmethylene-1,3-dithietane 2-propionylmethylene-1,3-dithietane2-butyrylmethylene-1,3-dithietane 2-isobutyrylmethylene-1,3-dithietaneZ-pentanoylmethylene-1,3-dithietane 2-hexanoylmethylene-1,3-dithietaneZ-cyano (methoxycarb'onyl)methylene-1,3-dithietane2-cyano(propoxycarbonyl)methylene-1,3-dithietane2-cyano(isopropoxycarbonyl)methylene-1,3-dithietane 2-cyano(butoxycarbonyl)methylene-1,3-dithietane 2-cyano(t-butoxycarbonyl)methylene-1,3-dithietane 2-cyano(pentoxycarbonyl)methylene-1,3-dithietane 2-cyano(hexoxycarbonyl)methylene-1,3-dithietane 2-cyano (carbamyl) methylene- 1,3-dithietane2-cyano(methylcarbamyl)methylene-1,3dithietane 2-cyano (ethylcarbamyl)methylene-1,3-dithietane 2-cyano (propylcarbamyl)methylene-1,3-dithietane 2-cyano (hexylcarbamyl)methylene-1,3-dithietaneThe 2 sulfonylimino-1,3-dithietanes of this invention may be made by thefollowing sequence of reactions:

S -alkali salt alkali R SOaNHa OS: R1S02N=C S-alkali salt (IV) YCHZY' i(Y and Y =01, Br, SCN) v) s 12 s OzN=C oH,

wherein R is as defined above.

The general method is known from US. Pat. 3,322,- 788 in the preparationof RSO N=C(SNa) and RSO N=C(SK) compounds and subsequent alkylations.

The reaction of a sulfonamide with CS and sodium or potassium hydroxideis preferably run in the presence of a solvent. Suitable solvents aredimethylformamide and dimethylsulfoxide. A temperature in the range of lto 50 C. is suitable, but a range of -30 C. is preferred.

The reaction of a compound of Formula IV with a methylene dihalide orhalothiocyanate is usually run in a solvent, e.g. an aromatichydrocarbon such as benzene, a ketone such as acetone, a nitrile such asacetonitrile, dimethylformamide or dimethylsulfoxide. Compounds ofFormula V, YCH Y', which are suitable for the reaction include methylenebromide, methylene chloride, methylene iodide and chloromethylthiocyanate. Temperatures in the range of -200 C. may be used and therefluxing temperature of the reaction mixture is often used with a rangeof 50l50 C. being preferred.

The use of chloromethyl thiocyanate is a novel procedure which resultsin enhanced yields of the desired dithietane. For example, Addor in I.of Het. Chem. 7, 381 (1970) reports a yield of 2-benzenesulfonylimino-1,3-dithietane of 2% when methylene bromide was used as the alkylatingagent. The same reaction when chloromethyl thiocyanate was used in thisstudy gave a 29% yield of the same product. Other examples of anincreased yield when chloromethyl thiocyanate is used are given below.

Another procedure whereby 2-sulfonylimino-1,3-dithietanes of Formula IImay be made is by reaction of a sulfonyl halide, e.g. a sulfonylchloride, with 2-imino-1,3- dithietane or its salts. The reaction may beillustrated by the following scheme:

b s R SOzCl+ HN=C 0H, R s 01N=o CHz s s (II) The reaction may be run inaqueous solution or in organic solvents such as an aromatic hydrocarbon,a ketone, or dimethylformamide. Typical bases which may be used includesodium or potassium hydroxide or carbonate, sodium acetate, alkalineearth carbonates or tertiary amines such as triethylamine. Example 5 ofUS. Pat. 3,484,455 describes a method for preparing 2-imino1,3-dithietane hydrochloride by hydrolysis ofZ-diethoxyphosphinylimino-1,3-dithietane with concentrated hydrochloricacid.

The Z-methylene-1,3-dithietanes of this invention may be made by thefollowing procedure:

R S alkali metal IR S C=G YCHzY' C=C CHz R S alkali metal R S (VI) (V)(III) The definitions of R R Y and Y are as given above.

Any active methylene compound which will react with carbon disulfide anda base will give a compound of the type of Formula VI. Active methylenecompounds of this type include NO CH (NC) CH R OC(O)CH CN, R OC(O)CHC(O)OR R C(O)CH wherein R R and R have the above meanings.

The preparation of di-alkali metal salts of1,1-dimercapto-2,2-dicyanoethylene as described in US. Pat. 2,533,233and discussed by Dittmer et al. in J. Organic Chemistry 29, 497 (1964)is typical of the preparation of compounds of Formula VI. The reactionof the compounds of Formula VI with YCH Y' compounds to producecompounds of Formula H1 is as described above for the preparation ofcompounds of Formula II with YCH Y compounds.

The following examples are presented in order to illustrate the typicalmethods of preparation and are not intended to limit the invention.

EXAMPLE 1 Preparation of 2-methylsulfonylimino-1,3-dithietane A slurryof dipotassium N-(methylsulfonyl)dithioimidocarbonate (20.8 g., 0.084mole) made by the method of Hartke, Arch. Pharm. 299, 174 (1966),chloromethyl thiocyanate (10 g., 0.092 mole) and acetone ml.) wasstirred at reflux for 4 hours then overnight at ambient temperature. Thereaction mixture was filtered and acetone was stripped from thefiltrate. The residue was taken up in chloroform (250 ml.) washed twicewith water, dried over sodium sulfate and the chloroform stripped off togive 11 g. of crude solid. This was recrystallized from ethanol withcharcoaling to give 8.3 g. of solid melting at 125127 C. This is a 54%yield of Z-methylsulfonylimino-l,3-dithietane.

The above reaction was repeated using methylene iodide instead ofchloromethyl thiocyanate and acetonitrile instead of acetone. Thereaction mixture was refluxed 48 hrs. after which the product wasisolated as above to give a 19% yield of recrystallizedZ-methylsulfonylimino-1,3- dithietane.

EXAMPLE 2 Preparation of 2 -ethylsulfonylimino-1,3-dithietane (a)Preparation of dipotassium N-(ethylsulfonyl)dithioimidocarbonate: To aslurry containing ethanesulfonamide (50.0 g., 0.459 mole), potassiumhydroxide (25.6 g., 0.459 mole) and dimethyl formamide (300 ml.) wasadded carbon disulfide (34.8 g., 0.459 mole). The resulting red slurrywas stirred for 2 hours maintaining the temperature below 35 C.Additional potassium hydroxide (25.6 g. or 0.459 mole) was then added.The temperature rose to 50 C. with the formation of a clear solution.After one hour, the temperature returned to ambient temperature, withformation of a precipitate. The precipitate was filtered, washed withdimethyl formamide and dried in the vacuum oven to give 95.8 g. ofdipotassium N-(ethylsulfonyl)dithioimidocarbonate melting at 213-217 C.

(b) Preparation of 2-ethylsulfonylimino-1,3-dithietane: A slurry ofdipotassium N- (ethylsulfonyl)dithioimidocarbonate (20 g., 0.0766 mole),chloromethyl thiocyanate (9.9 g., 0.0919 mole) and acetone (175 ml.) wasstirred at reflux for 2 hours then at ambient temperature for 16 hours.The reaction mixture was filtered and acetone was stripped from thefiltrate. The residue was taken up in chloroform, washed with water,dried and the chloroform stripped ofi. The residue was recrystallizedfrom ethanol to give 1.2 g. (8%) of Z-ethylsulfonylimino-1,3-dithietane.

EXAMPLE 6 Preparation of Z-benzenesulfonylimino-1,3-dithietaneChloromethyl thiocyanate (7.2 g., 0.0674 mole) was added to a slurry ofdipotassium N-(phenylsulfonyl) dithioimidocarbonate (10 g., 0.0324mole). After the reaction proceeded at ambient temperature for twohours, the reaction mixture was diluted with water (200 ml.) and theresulting solid was collected. The crude reaction product was washedwith water and recrystallized from ethanol to give 2.3 g. (29%) of2-benzenesulfonylimino-1,3- dithietane.

EXAMPLE 7 Preparation of 2-p-nitrophenylsulfonylimino-1,3-

dithietane Sodium bicarbonate (2.96 g., 0.0353 mole) was addedportionwise at 5 C. to a slurry of 2-imino-1,3-dithietane hydrochloride(2.5 g., 0.0176 mole), and p-nitrobenzenesulfonyl chloride (4.72 g.,0.0214 mole) in acetone (150 ml.). The stirring was continued at 5 C.for 30 minutes and then at ambient temperatures for 18 hours. Afterfiltration and solvent removal, the residue was dissolved in chloroform(400 ml.) and washed twice with 5% aqueous hydrochloric acid (50 ml.),water, 5% aqueous sodium hydroxide, and water. After solvent removal,the residual material was recrystallized from ethanol to give 2.7 g.(53%) of 2-p-nitrophenylsulfonylimino 1,3 dithietane melting at 170172C.

EXAMPLE 12 Preparation of Z-nitromethylene-1,3-dithietane An acetone(200 ml.) slurry of dipotassio-1,1-dithio- 2-nitro-ethylene (21.3 g.,0.1 mole) and chloromethyl thiocyanate (10.7 g., 0.1 mole) was refluxedfor 2 hours and allowed to proceed at ambient temperature for anadditional eighteen hours Additional chloromethyl thiocyanate (10.7 g.,0.1 mole) was added and the slurry refluxed for an additional eighthours and then allowed to proceed at ambient temperature for eighteenhours. The slurry was filtered and the filtrate was evaporated. Theresulting solid material was extracted with hot chloroform. Thechloroform was evaporated and the residue was recrystallized twice fromethanol to give 2.0 g. (13%) of 2-nitromethylene-1,3,-dithietane meltingat 169-170 C.

6 EXAMPLE 13 Preparation of 2-acetonylidene-1,3-dithietane A mixture ofacetone (14.5 g., 0.25 mole) and carbon disulfide (19.0 g., 0.25 mole)was added dropwise at 10 C. to a slurry of potassium-t-butoxide (56.0g., 0.5 mole) in benzene (500 ml.). The slurry was stirred at ambienttemperature for eighteen hours, and then methylene iodide (134.0 g., 0.5mole) was added. After stirring at ambient temperature for one hour, themixture was heated on a steam bath for two hours. After stirring foreighteen additional hours at ambient temperature, the reaction mxiturewas filtered and the filtrate was removed. Residual methylene iodide wasremoved by vacuum distillation. The residue was dissolved in chloroform,washed with 2% aqueous hydrochloric acid, water, 2% aqueous sodiumhydroxide, water, dried over sodium sulfate, and the solvent removed toleave 6.0 g. (16%) of an oil, which is 2-acetonylidene-1,3-dithietane.

EXAMPLE 17 Preparation of 2-(carbamyl-cyanomethylene) 1,3-dithietane Anacetonitrile (100 ml.) slurry of dipotassio-1,1-dithio-2-carbamyl-2-cyano-ethylene (23.6 g., 0.1 mole) and methyleneiodide (26.8 g., 0.1 mole) was heated to reflux for eighteen hours. Theslurry was filtered and the solids extracted with additionalacetonitrile (100 ml.). The combined acetonitrile solutions wereevaporated to dryness. The residue was treated with hot acetone andcharcoal and then diluted with ether until precipitation commenced. Theprecipitate was filtered, the filtrate evaporated and the residue wascrystallized twice from ethanol to give 1.45 g. (8%) ofZ-(carbamyl-cyanomethylene)-1,3-dithietane melting at 205-206 C.

EXAMPLE 25 Preparation of 2-bromonitromethylene-1,3-dithietane To asolution of 2-nitromethylene-1,3-dithietane (5 g., 0.0336 mole) inchloroform (1 l.) was added a solution of bromine (5.37 g., 0.0336 mole)in chloroform ml.) dropwise. The solution was stirred 18 hrs. and thesolvent removed to leave 7.5 g. of solid residue. This wasrecrystallized from ethanol to give 2 g. of2-bromonitromethylene-1,3-dithietane.

Table I below gives details on typical preparations of2-sulfonylimino-1,3-dithietanes. Table II below gives details on typicalpreparations of 2-methylene-1,3- dithietanes.

TABLE I Physical Constants of 2-SulIonyl1m1no-1,3-Dithletanes R SOgN=C/CH,

Analysis (percent) Melting Found Theory point, Empirical Ex. R C.formula C H N 0 S C H N 0 S 1 OH: 126-127 CsHsNOzsa 19.7 2.9 7.5 17.852.5 19.6 2.7 7.7 17.5 52.5 64-66 C4H1NO2Sa 24.6 3.6 7.0 16.2 48.6 24.43.5 7.1 16.2 48.7 -61 CsHoNOzSs 28.2 4.4 6.5 15.5 45.7 28.4 4.2 6.6 15.245.5 54-55 CroHioNOzSa 42.9 6.9 5.0 11.6 34.1 42.7 6.7 5.0 11.4 34.23913(1) oomNozsa 41.8 3.6 5.4 13.8 36.3 41.8 3.5 5.4 12.3 37.0 171-172OaHuNa04Sa 33.7 2.2 9.6 22.3 32.1 33.1 2.1 9.6 22.1 33.1 8 o 4 -141CgHqClNOzSa 34.5 2.3 5.1 11.7 32.7 34.4 2.1 5.0 11.5 34.4 9 4-CH C H147-149 C HoNOaS; 41.6 3.6 5.3 11.9 34.1 41.7 3.5 5.3 12.4 37.1

10...: :N 78-79 CIHHNZOZSI 33.7 5.0 11.2 13.1 36.5 33.3 4.8 11.1 12.738.1

11-...-. (CHzhN 79-80 C4H Nn0 S 23.1 4.1 13.1 15.1 45.2 22.6 3.8 13.215.2 45.3

I. Heteroeyclie Chem. 7, 381 (1970):

TABLE II Physical Constants of 2-Methylene-1,3-Dithietanes Analysis(percent) Theory Found Melting point. 0. Empirical formula 167-169 CaHaNOzSz conc, CsHeO S: 119-121 CmH O S 139440 CHaCO CaHnCO Org. Chem. 29.497 (1964).

The compounds of this invention are useful as biocides and in particularhave exhibited excellent herbicidal, microbicidal, molluscicidal andnematocidal activity. For convenience these compounds will at times bereferred to generally as 1,3-dithietanes.

The compositions of the invention when used as agricultural pesticidescomprise a 1,3-dithietane together with an agronomically acceptablecarrier. By an agronomically acceptable carrier is meant any substancewhich can be used to dissolve, disperse, on diffuse the chemical withinit, without impairing the effectiveness of the toxic agent, which is notpermanently deleterious to the soil in any chemical or physical mannerand which is usually non-phytocidal to the agricultural crops to beprotected. The compositions may be in the form of solutions,emulsifiable concentrates, Wettable powders, granules, or dusts. One ormore liquid or solid carriers may be used for a particular herbicidalcomposition.

An emulsifiable concentrate is made by dissolving a 1,3-dithietane in asolvent to which one or more surfactants are added. Suitable solvents orliquid carriers for use in preparing these emulsifiable concentratesmay, for example, be found in the hydrocarbon and ketone classes oforganic solvents such as xylene, acetone, isophorone, mcsityl oxide,cyclohexanone and mixtures of these. Preferred solvents areketone-hydrocarbon mixtures such as isophorone-xylene. The emulsifyingagents used are surfactants of the anionic, cationic, or non-ionic typesand mixtures thereof. Representative of the anionic surfactants arefatty alcohol sodium sulfates, calcium alkylbenzensulfonates and sodiumdialkyl sulfosuccinates. Representative of the cationics are (higheralkyl) dimethylbenzylammonium chlorides. Representative of the nonionicsare condensation products of alkylene oxides with fatty alcohols, alkylphenols, mercaptans, amines or fatty acids, such asdinonylphenoxypolyethoxyethanol in which there are 8 to 100 ethergroupings and similar polyethoxy compounds prepared with otherhydrophilic groupings, including esters of long chain fatty acids andmannitan or sorbitan, which are reacted with ethylene oxide.

The following compositions are typical of emulsifiable concentrateformulations when solvents are used.

Parts/100 parts total 1,3-dithietane 10-35 Solvent 55-88 Emulsifyingagent 2-l0 Wettable powder formulations comprise a 1,3-dithietaneadmixed in a solid carrier along with a surface active agent(s) whichgives this type of formulation its wettability, dispersibility andspreading characteristics. Solid carriers which are suitable forpreparing these Wettable powder formulations are those which have beenrendered agronomically suitable by pulverizing devices and may beorganic or inorganic in nature. Suitable organic carriers are soybean,walnut or wood flower or tobacco dust; and suitable inorganic ones areclays of the montmorillonite (bentonite), kaolinite or fullers earthtypes; silicas such as diatomaceous earth and hydrated silica; silicatessuch as talc, pyrophylite, or alkaline earth silicates, and calcium andmagnesium carbonates. A surfactant or mixture of surfactants is added tothe Wettable powder formulation. Suitable dispersing agents are sodiumlignin sulfonate, sodium formaldehyde-naphthalene sulfonate, or sodiumN-methyl-N-higher alkyl taurates. Wetting agents useful for this purposeinclude higher alkylaryl sulfonates such as calciumdodecylbenzenesulfonate, long-chain a1- cohol sulfates, sodiumalkylphenoxypolyethoxyethyl sulfonates, sodium dioctyl sulfosuccinate,and ethylene oxide adducts with fatty alcohols or with higheralkylphenols, such as octylphenoxypolyethoxyethanol in which there are 8to ether groupings and similar polyethoxy compounds made from stearylalcohol. Operative spreading or adhesive agents include glycerolmannitan laurate or a condensate of polyglycerol and oleic acid modifiedwith 1,3-dithietane 20-80 Carrier -79 Surfactants 1-10 Dust concentratesare made by incorporating a 1,3- dithietane of this invention into asolid carrier such as finely powdered clays, talc, silica and syntheticsilicates, alkaline earth carbonates and diluents of natural origin,such as tobacco dust or walnut shell flour. Granular formulations aremade from similar type solid carriers except that the particle size islarger, in the range of to 60 mesh. A small amount of dispersing agentmay be incorporated into these solid formulations. The concentration ofactive ingredients in these dust or granular formulations may be in therange of 2 to 15% It will be seen from the above that the compositionsof this invention may contain to 98% of carrier based on the totalweight of the composition, depending on whether it is in the form of asolution, an emulsifiable concentrate, a Wettable powder, a dust or agranular formulation. Solutions containing a relatively high percentageof the active ingredient are used for applications by a low volumetechnique.

A particularly convenient method for making solid formulations is todissolve the active ingredient in a volatile solvent, such as acetone;apply this solution to the solid carrier with thorough mixing, and thenremove the solvent by allowing it to evaporate at either normal orreduced pressure.

The compounds of this invention were evaluated in standard greenhousetests. For these tests, seeds of selected crops and weeds were plantedin soil. For preemergence tests, the pots or flats were treatedimmediately with the test compound. For postemergence tests, the seedswere allowed to germinate and the plants to grow for two weeks at whichtime they were treated by foliar application with the test chemical. Inthe preliminary evaluation, the rate of application was 10 pounds peracre (11 kilos per hectare) using four representative monocotyledonousplants, viz.

barnyardgrass (Echinochloa crusgalli), crab grass (Digitariaanguinalis), Johnsongrass (Sorghum halepense) and wild oat (Avenafatua),

and four representative dicotyledonous plants, viz.

bindweed (Convolvulus arvensis) curly dock (Rumex crispus) velvetleaf(Abutilon theophrasti) and wild mustard (Brassica kaber).

In a secondary herbicidal evaluation additional plant species wereplanted in flats. For the monocotyledonous plants these included:

Bermudagrass (Cynodon dactylon), downy brome (Bromus tectorum), foxtail(Setaria glauca),

nutsedge (Cyperus esculentus), quackgrass (Agropyron repens), ryegrass(Lolium multiflorum) and witchgrass (Panicum capillare).

For the dicotyledonous plants these included:

cocklebur (Xanthium pensylvam'cum), lambsquarters (Chewopodium album),morningglory (Ipomoea purpurea), pigweed (Amaranthus retroflexus),

smartweed (Polygonum pensylvanicum) and wild carrot (Daucus carota).

In these standard greenhouse tests the percent control for each plantwas read two weeks after treatment and the values reported as an averagepercent control for the monocotyledons (M) and the dicotyledons (D).Table III gives the results.

TABLE III Herbicidal Evaluations on 1,3'dithiet'anes X=C\ /0HHerbicidal, percent control Preemergence Postemergence Example 10lbs./a. 4 lbs./a. 10 lbs./a. 4 lbs./a.

1. M 70 32 77 42 97 67 95 2. 67 2 77 42 75 33 97 75 3. 70 5 80 45 87 28100 73 4. 0 0 45 6 22 0 70 10 5. 30 0 6O 2 27 0 67 2 6. 25 5 30 0 62 1150 11 7. 0 0 50 0 0 0 70 0 8. 22 0 7 0 0 0 25 0 9. 22 0 0 0 0 87 0 10. M0 6 62 3 30 16 82 14 11. 25 5 67 6 35 12 36 12. 82 13 65 Y 36 92 40 9257 13. 0 0 42 0 25 0 62 6 14. 0 0 30 0 0 92 15. 75 26 87 51 35 95 91 16.0 0 45 8 25 0 72 15 17. 37 0 42 0 77 0 92 17 18. 0 0 30 2 19. 0 30 0 5220. 0 5 0 32 21. 0 7 22. 0 0 25. 50 50 Representative compounds of thisinvention have demonstrated excellent control of aquatic weeds. For thistest submersed species of aquatic weeds were planted in 1.5 inch pots ina 50:50 mixture of sand and soil and the pots placed in a one-gallonjar. Water (3000 ml.) was added. Floating species of aquatic weeds werethen placed on the top of the water. The jars were held for two weeksduring which time water lost by evaporation was replaced at weeklyintervals. The test compound was dissolved in acetone and amounts ofthis solution were then added to the jar such that the concentration ofthe compound in the water was in varying ranges from 0.5 to 10 p.p.m.Two weeks after treatment the percent control was read.

The following aquatic weed species were used:

Floating species:

A azolla Azolla caroliniana B duckweed Lemna minor C Spirodela Spirodelwpolyrhiza D Salvinia Salvinia rotundifolia E water fern Ceratoptristhalictroides Submersed species:

F cattail Typha latifolia G Elodea Elodea canadensis H Ludwigia Ludwigiaspp.

Table IV gives the results.

TABLE 1V.AQUATIC WEED CONTROL A B C D E F G H Rate, Duck- Spiro- 8111-Water Cat- Lud- Ex. p.p.m Azolla weed dela vinia fern tail Elodea wigia1 5 so 95 50 0.5 40 25 70 4 2.5 90 so 95 5 40 50 5 0 s0 50 0.5 75 o 25 72.5 100 90 so 5 60 so 60 0.5 0 0 0 9 2.5 100 50 95' 5 100 50 100 10 5 00 50 0.5 100 30 60 11 2.5 55 50 70 5 75 85 85 13 5 o 0 30 0.5 o 25 0 152.5 0 95 50 5 85 0.5 15 15 0 16 2.5 75 5 90 100 50 17 5 0 15 1 30 0 0 1s5 so 65 0 10 so 80 19 5 0 80 5o 1 0 55 0 20 5 30 70 40 10 60 so 50 1 0 00 21 5 0 0 0 10 0 35 o The compounds of this invention have been foundto Certain of the 1,3-d1th1etanes have exhibited nematopossess excellentmolluscicidal activity. 4 cidal activity.

Evaluations were made on the Biomphalaria glabratus, a known vector ofschistosomiasis or bilharziasis. Young snails (5-10 mm. diameter) wereexposed to aqueous dispersions containing various concentrations of the1,3-dithietane. For this test five to ten snails were placed in 6 oz.cups containing ml. of the dispersion prepared with non-chlorinatedwater. After a 24-hour exposure period followed by a 24-hour recoveryperiod in untreated, non-chlorinated water the percent mortality wasdetermined.

The results of the test are summarized in Table V. The concentrationsare given in parts per million (p.p.m.).

TABLE V.-MOLLUSCICIDAL ACTIVITY Percentage kill of biomphalan'aglabratus, p.p.m.

Example 0. 15

In the same test, compounds of US. Pat. 3,484,455, e.g.2-imino-l,3-dithietane hydrochloride, 2-methylimino- 1,3-dithietane, and2-methylcarbamylimino-1,3-dithietane gave no kill of the snails at 12p.p.m.

For the nematode test, soil was homogeneously inoculated with amacerated blend of tomato roots heavily knotted with the root-knotnematode, Meloidogyne hapla. Ten ml. of the test solution was added to200 ml. of the inoculated soil in a 16 oz. jar to give a concentrationby volume of about 60 p.p.m. The jar was then shaken to insure thoroughmixing and kept capped for 72 hours. The soil was then placed into a 3"plastic plant pot and allowed to air for about 24 hours after which time3 cucumber (Cucumis sativus) seeds were planted. About twentythree daysthereafter, the cucumber plants were removed from the soil and the rootsystems examined for the presence of knots. A total of 11 knots isconsidered as no control (NC) and less than that as a measure ofcontrol.

Under these test conditions, the herbicidal tendencies of candidatematerials are often expressed. Where cucumber seedlings fail to emerge(germinate) or emerge and then rapidly succumb due to phytotoxicity,assessment of knotting on roots is not possible. In such instances, aweek prior to the scheduled observation date, an excised, healthycucumber leaf (usually cotyledonary rather than primary leaf) is buriedin the soil of the treatment. On the observation date the efficacy ofthe treatment is established by microscopic examination (stereo 20X) ofca. 0.5 cc. soil samples taken from the zone containing plant fragments(the above leaf, or remnants of roots, stems, leaves, and even seeds ofthe original sowing can be used). Ineffective treatments are thusdetected by an abundance of live nematodes in water slurries of suchsoil samples. A measure of control is denoted by the total absence ofnematodes or numbers less than 5 per sample.

Lower concentrations of example materials are obtained by using likevolumes of test solutions at appropriate solution strengths.

The results of the tests are summarized in Table VI.

TABLE VL-NEMATOCIDAL ACTIVITY Number Meloidogyne hapla in soil or numberknots on cucumber roots P.p.m. in soil.-- 60 The 1,3-dithietanes of thisinvention are biocidally active compounds, and as such, are suitable forthe control of living organisms and particularly microorganisms.Representative compounds have been found to be effective algaecidal,bactericidal and fungicidal agents and are useful as industrialbiocides.

One method of evaluation used was by a procedure known as an agar streaktest. In this test the compounds to be examined were dissolved in anappropriate solvent and added to two sterily Petri plates in an amountnecessary to provide a given concentration of the compound in parts permillion (p.p.m.) when diluted with sterile trypticase broth-dextroseagar for fungi and bacteria or inorganic salts agar for algae. Thecompound and the agar were thoroughly mixed and allowed to harden. Theagar surface was streaked with agaror liquid-grown cultures ofrepresentative bacteria, fungi or algae. The plates were then incubatedat the appropriate time, temperature and illumination for the givenculture and then observed for inhibition of growth on the agar surface.The following system was employed to rate the activity of the compounds.

=complete inhibition 1+=slight growth 2+=moderate inhibition 3+=slightinhibition 4+=no inhibition Table VII gives the results using threebacteria Pseudomonas aeruginosa (P. aerug.), Staphylococcus aureus (S.awreus) and Escherichia coli ('E. coli); three fungi Aspergillus fiiger(A. niger), Rhizopus stolonifer (Rhiz.) and Rhodotorula rubra (Rhod.)and three algae Chlorella pyrenoidosa (Chlorella), Scenedesmus obliquus(Scene.) and Phormidium spp. (Black).

The compounds of this invention may be readily utilized as algaecides,bactericides, fungicides, mildewicides, slimicides or combinationsthereof in any loci by incorporating into said loci a 1,3-dithietane inan amount which is effective to control the microorganism(s) present.

One such application is the control of microorganisms in aqueous mediasuch as water-cooling systems, swimming pools, paper pulp processes,aqueous polymer dispersions, water-based paints, and the like. Forexample, the compound of Example 15 at 25 p.p.m. gave excellent controlof algae and slime in laboratory model cooling tower tests.

The compounds are useful biocides in other liquid media such as thoseused in the cosmetic, fuel, metal-working and paint industries. Forexample, the compound of Examples 12 and 15 were found to be effectivepreservatives for cutting oils at 250-1000 p.p.m. The compounds ofExamples 12 and 16 were active in paint film mildewicide applicationtests.

The 1,3-dithietanes and compositions containing them can also functionas fabric and leather preservatives, cosmetic preservatives, soapadditives, sanitizing agents such as in laundry soaps and detergents,preservatives for fuels, fiber spin finish biocides and the like.

The exact amount of 1,3-dithietane required to achieve the microbiocidaleffect will, of course, vary with the medium being protected orpreserved ,the microorganisms being controlled, the particular1,3-dithietane or composition thereof being employed and the like.Typically, in a liquid medium, excellent control may be obtained wherethe 1,3-dithietane is incorporated in the range of 0.1 to 10,000 partsper million or 0.00001 to 1% based on the weight of the medium. A rangeof 1 to 2000 p.p.m. is preferred.

I claim: 1. A compound of the structure o=o CHz wherein R is hydrogen,bromo, chloro, cyano, an R OC(O)-group wherein R is a lower alkyl group,N (3,4-dichlorophenyl)carbamyl, N-(4-dimethylaminophenyl)carbamyl orN-(4-nitrophenyl)carbamyl; when R is hydrogen, R is nitro or an RC(O)-group wherein R is a lower alkyl group or a phenyl group; when R isbromo or chloro R is nitro; when R is cyano R is an R OC(O)-groupwherein R is a lower alkyl group, an R NHC(O)-group wherein R ishydrogen or a lower alkyl group or an R 50 group wherein R is phenyl,phenyl substituted with lower alkyl, lower alkoxy, halogen or nitro, ora lower alkyl group; when R is an R OC(O)-group R is an R OC(O)-groupwherein R is a lower alkyl group; when R is N-(3,4-dichlorophenyl)carbamyl, N-(4-dimethylaminophenyl)carbamyl or N-(4- TABLE VIL-CONTROLOF MICROO RGANISMS (RANK IN ST REAK TEST) Bacteria 1 Fungi 1 Algae S. E.A. auems colt nz'ger Rhiz. Rhod. Chlor Scene. Black 1 T0'l1.-C0nl;rO1ZConcentration of eompound=500 p.p.m.; 2 Concentration of compound=20p.p.m.

nitrophenyl)carbamyl R is arenesulfonyl wherein arene is benzene,naphthalene or benzene substituted with lower alkyl, lower alkoxy,halogen or nitro. 2. A compound of the structure C=C\ /C Ozb/ S whereinR is hydrogen, bromo or chloro.

3. A compound according to claim 2 which is2-nitromethylene-1,3-dithietane.

4. A method for preparing a compound of the structure wherein R ishydrogen, bromo, chloro, cyano, and R OC(O)-group wherein R is a loweralkyl group, N- (3,4 dichlorophenyl) carbamyl, N(4-dimethylaminophenyl)carbamyl or N-(4-nitrophenyl)carbamyl; when R ishydrogen R is cyano, nitro or an R C(O)-group wherein R is a lower alkylgroup or a phenyl group; when R is bromo or chloro R is nitro; when R iscyano R is cyano, an R OC(O)-group wherein R is a lower alkyl group, anR NHC(O)-group wherein R is hydrogen or a lower alkyl group or an R 80group wherein R is phenyl, phenyl substituted with lower alkyl, loweralkoxy, halogen or nitro, or a lower alkyl group; when R is an ROC(O)-group R is an R OC(O)-group wherein R is a lower alkyl group; whenR is N-(3,4-dichloropheny1)carbamyl, N- (4-dimethylaminophenyl car- 16bamyl or N-(4-nitrophenyl)carbamyl R is arenesulfonyl wherein arene isbenzene, naphthalene or benzene substituted with lower alkyl, loweralkoxy, halogen or nitro, which comprises reacting a compound of thestructure S -alkali salt UNITED STATES PATENTS 5/1967 Gompper et al.260-327 M OTHER REFERENCES Addor, I. Heterocyclic Chemistry, vol. 7, pp.381-387 (April 1970).

Houben-Weyl, Methoden der Organischen Chemie, 4th ed., vol. 9, pp.794-796 and 866, Georg Thieme Verlag, Stuttgart, Germany (1955).

JOHN D. RANDOLPH, Primary Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,772,331 Dated November 13 1973 Inventor(s) Stanley A. Greenfield It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the specification make the following changes:

Column 1, line 1-7, R should read "R Column 2, line 10, "R should read--R Column 2, line 16, "R should read -'R (SEAL) Attest:

EDWARD ILFLETCHEII,JR. C. MARSHALL DANN Attestingg Officer Commissionerof Patents

